{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA9978-0BB24","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA9978-0BB24","canonicalUrl":"https://aoctrl.com/siemens/3VA9978-0BB24","factsUrl":"https://aoctrl.com/api/mcp/products/3VA9978-0BB24","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA9978-0BB24, undervoltage release accessory, 120-127V AC 50/60Hz, 2 VA, 4 kV surge, for 3VA4/5/6 breakers.","salesMarkdown":"The Siemens SENTRON 3VA9978-0BB24 is an undervoltage release accessory designed for 3VA4, 3VA5, and 3VA6 molded-case circuit breakers. It trips the breaker when supply voltage drops below the release threshold, protecting motors and sensitive loads from undervoltage conditions. The 4 kV surge voltage resistance ensures it withstands switching transients common in motor circuits without failing. The 3-slot design and compact dimensions — 28.8 mm deep, 25.7 mm wide, 65.1 mm high — allow it to snap into the accessory slot of the host breaker without increasing the panel's DIN-rail footprint. Stripped length of 10 mm (0.4 in) on the auxiliary circuit connection (AWG18 / 750 mm) is the standard for panel wiring.","metaTitle":"Siemens 3VA9978-0BB24 SENTRON Undervoltage Release, 120-127V","metaDescription":"Siemens SENTRON 3VA9978-0BB24 undervoltage release accessory for 3VA4/5/6 breakers. 120-127V AC 50/60Hz, 2 VA, 4 kV surge. Active production, sourced to order. Request quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Breaker Accessories"],"specifications":{"Depth":"28.8 mm","Width":"25.7 mm","title":"3VA9978-0BB24","Height":"65.1 mm","Accessories":"Auxiliary release","description":"undervoltage release 120-127V AC 50/60Hz accessory for: 3VA4/5/6","Number Of Slots":"3","Stripped Length":"10 mm","lifecycle_stage":"current","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Accessories","Overvoltage Category":"III","Stripped Length [In]":"0.4 in","Design Of The Product":"auxiliary release","Surge Voltage Resistance":"4 kV","Apparent Power Consumption / Maximum":"2 VA","Type Of Electrical Connection / For Auxiliary Circuit":"AWG18 / 750 mm"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$53.34","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/317fe613d5e7e4cd506e118ace58efa6.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=650525&mlfb=3VA9978-0BB24"},"ai":{"faq":[{"question":"What is 3VA9978-0BB24 used for?","answer":"It is an undervoltage release accessory for Siemens SENTRON 3VA4, 3VA5, and 3VA6 molded-case circuit breakers, tripping the breaker when supply voltage drops below the release threshold to protect downstream equipment."},{"question":"Where can I buy 3VA9978-0BB24 and how is it quoted?","answer":"The part is sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time."},{"question":"What are the key specifications of 3VA9978-0BB24?","answer":"It is rated 120-127V AC 50/60 Hz, 2 VA maximum apparent power, 4 kV surge voltage resistance, overvoltage category III, pollution degree 3, with dimensions 28.8 x 25.7 x 65.1 mm."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA9978-0BB24","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/3VA9978-0BB24 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}